4 Ken-Rad 6K6 6K6GT Vacuum Tubes Valves Black Glass Lot Of Four December 25 2024 O getter and an 805

O getter and an 805 ACP date / provenance code

This matched trio of RCA 5Z4 rectifier tubes were tested on our Paul Hart-calibrated TV7/U for shorts

new in box GE 12FX8A tubes tested to spec on our Paul Hart-calibrated TV7/U

new in box RCA 6AV5 tubes tested to spec on our Paul Hart-calibrated TV7/U

Transconductance measured 48 for Tube One and 50 for Tube Two where minimum (65%) is 40 and 100% is 62

4 Ken-Rad 6K6 6K6GT Vacuum Tubes Valves Black Glass Lot Of Four December 25 2024 O getter and an 805These Ken Rad MANUFACTURED, OEM BRANDED black glass 6K6GT tubes were tested on our Maxi Matcher tube tester with 325 volts on the plates and a bias of 36 volts and tested as follows: Tube One: 20 milliamps' plate current, 1480 micromhos' transconductance; Tube Two: 21. 9 1700; Tube Three: 23. 9 1730 and Tube Four: 34 2240 where new nominal is within one standard deviation of 1900. Sorry I cannot say how they sound, but I have not been able to find a